Rheostat



C. H. TEEGARDEN.

RHEOSTAT.

APPLICATlON FILED OCT 18.1918.

Patented June 7, 1921.

[area far- C/btait/ff. fiejarden CHESTER H. TEEGARDEN, OF WASHINGTON,DISTRICT OF .COLUMBIA mmos'mr.

I Specification of Letters Patent.

Patented June '7, 1921.

Application filed October 18, 1918. Serial No. 258,752.

T 0 all whom it may concern Be it known that I, CHESTER H. TEEGAR- DEN,a citizen of the United States, and a resident of Washington, in theDistrict of Columbia, have invented certain new and useful Improvementsin Rheostats, of which the following is a specification.

My invention relates to rheostats and in particular to a rheostat usedin connection with other devices to form a potentiometer for use intelegraphy. One of the objects of my invention is to provide a rheostatwhich may be encompassed in a minimum possible space and which is ofrugged construction and simple design. In order to carry out this objectI have incorporated in my rheostat novel features and the connectionbetween these features and this object of the invention will appear asmy device is de scribed.

In the drawings I have illustrated the embodiment of my device which Inow prefer. In these drawings Figure 1 represents a side elevation of myrheostat; Fig. 2 represents a central section; and Fig. 3 represents abottom plan; Fig. 4 is a diagram of the wirin system showing the courseof the circuit.

Iy rheostat comprises a U-shaped frame 1 provided with two resistors 2and 3 se- ('ured thereto across the open end thereof. Each resistor isprovided with a core 4 of insulating material which is covered with asingle layer. of wire 6. This wire is inter rupted midway to permit theinsertion of a metal strip 5 in which is inserted an insulating plug 7interposed in the path of contact of the contact arm 12 or 13 whichmoves over that resistor. These arms 12 and 13 are connected to a lever10 by means of the binding posts 15 and sleeve 15 but are insulated fromthis lever by means of the insulating segments 14. The lever 10 isprovided with a handle 11 and is pivoted in the ears 19 of the frame 1.Secured to the one end of the coil 2 is a cross connector 8 1 connectedwith the opposite end of the coil 3. The two remaining endsof the coils2 and 3 are connected by the cross connector 9. These cross-connectors 8and 9 are insulated from each other.

In the use for whichI have designed my rheostat it is desirable that thecontact arms 12 and 13 may be insulated from the resistance in themid-position and for this reason I have provided the insulating segments7 embedded in the metal strip 5. By the use of my U-shaped frame Isecure a very compact arrangement inasmuch as the resistors may bemounted across the open end of the frame while the contact arms may bepivoted at the base of the frame. Further the entire rheostat may besuitably mounted on the back of a panel by securing the flat base 16 ofthe frame 1 to theback of the panel and providing a proper openingwhereby the handle 11 may extend through the panel for operation fromthe'front thereof. By cross connecting the two resistors and causing thearms to move over them simultaneously I provide a novel arrangement forvarying the resistance.

'While I have described my resistors as consisting of an insulating corewound with a single layer of wire, and while I use an insulated wire andremove the insulation in the path of contact of the arms 12 and 13, I amaware that other methods of contact could be used, such for example, asthe provision of'a separate row of contact segments connected tointermediate points of the resistance winding. I am also aware that itmay be found desirable to use impedance other than resistance. Iconsider any such change to be within the scope of my invention and Ialso consider as within the scope of my invention all modifications orimprovements of my rheostat which are included in the scope oftheappended claims.

Having described the preferred embodiment of my invention,*I claim:

1. A rheostat comprising a U-shaped frame, a pair of impedance elementssupported side by side across the open end of said frame, a leverpivoted in said frame at the base thereof, two contact arms carried bysaid lever on opposite sides thereof, each contact arm being positionedto make wiping contact over the outer side of one of said impedanceelements, and an insulating segment interposed in each impedance elementto insulate that element from the arm at that point.

2. A rheostat comprising a U-shaped frame, a pair of impedance elementssupported across the open end of said frame, a lever pivoted in saidframe at the base thereof, two contact arms carried by said lever, eacharm being positioned to make wiping contact over one of said impedanceelements, and an insulating segment interposed in each impedance elementto insulate that element from the arm at that point.

ported across an open end of said frame, a

lever, two contact arms carried by said lever, means for respectivelyconnecting said arms with varying portions of said impedance elements,and an insulating segment interposed in each impedance-element toinsulate that element from the arm at that point.

4. A rheostat comprising a frame, a pair of impedance elementsoppositely supported by said frame, a lever, two oppositely extendingcontact arms carried by said lever, each arm being positionedto contactalong one of said impedance elements, and an insulating segmentinterposed in each impedance element to insulate that element from thearm at that point.

5. A rheostat comprising a U-shaped frame, a pair of impedance elementssupported across the open end of said frame, a lever, and two contactarms carried by said lever, each arm being positioned to contact, alongone of said impedance elements.

6. A rheostat comprising a frame, a pair of impedance elements supportedby said frame, contact means positioned to contact along said impedanceelements, and an insulating segment interposed in each impedance elementto insulate that element from the contact means at that point.

7. A rheostat comprising a U-shaped frame, a pair of impedance elementssupported across the open end of said frame, and contact meanspositioned to contact along saidimpedance elements.

8. A rheostat comprising an open ended frame, a pair of resistanceelements supported side by side across an open end of said frame, alever, two contact arms carried by'said lever, means for connecting saidcontact arms respectively with varying portions of said resistanceelements, an insulating element interposed in each resistance ele-' mentto insulate that element from one of said contact arms and meansconnecting one end of each of said resistance elements to the other endof the other of said resistanee elements, respectively.

lln testimony whereof ll affix my signature Q iRDEN

